Researchers test hundreds of artificial bone designs to strike a balance between strength and porosity.

Replacing human bones, whether because of trauma or defect, can be a painful process. Traditionally, surgeons use bone grafting to move bone from one part of the body to another. But researchers think artificial bones, custom-created using 3-D printing, could one day replace missing or injured bone without requiring the transplantation of existing bone fragments.

Toward that goal, an international team analyzed 240 different artificial bone graft designs. They 3-D printed those that were both porous, to allow mixing with natural bone and connective tissue, and strong, to withstand daily use. Physical tests of the 3-D printed designs revealed a few stand-outs. The more successful designs were up to 10 times stronger than the others and had properties similar to natural bone, meaning they are less likely to cause problems over the long term. Another advantage is that these artificial bone grafts could be custom-printed to potentially fit any patient.

The researchers published the results in July in the journal Materials & Design.

Although more testing is needed before these designs can be used clinically, the researchers’ ultimate goal is to produce a replacement that mimics real bone in humans. Their next step is to work on designs that will use a mix of two or more of the structures identified as especially strong and porous and see how they behave in biological systems.